Apparatus and method for removing cuttings



March 4, 1969 G. c. GAUNTT, JR., ETAL 3,430,448

APPARATUS AND METHOD FOR REMOVING CUTTINGS Filed July 12, 1967 FIGZ INVENTORS GROVER C. GAUNTT JR. ROBERT G. ISAACS ROBERT L. MARTIN JAMES P. WALTON PM 6 7M 4%- BY ATTORNEYS United States Patent 3,430,448 APPARATUS AND METHOD FOR REMOVING CUTTINGS Grover C. Gauntt, Jr., Itasca, Robert G. Isaacs, Roselle, and Robert L. Martin, Park Forest, 111., and James P. Walton, Santurce, Puerto Rico, assiguors to Case Foundation Company, Roselle, 11]., a corporation of California Filed July 12, 1967, Ser. No. 652,898 US. C]. 61-40 10 Claims Int. Cl. E21d 1/00, 5/00; E21b 21/00 ABSTRACT OF THE DISCLOSURE A core-barrel provided with teeth at one of the ends thereof for cutting into and penetrating bedrock or other sub-surface material in the production of caissons by rotation of the core-barrel. The core-barrel is equipped to serve as a pump which is designed to act in response to the vertical reciprocation of the core-barrel to pump water down through the core-barrel to remove cuttings in the sub-surface adjacent the teeth of the core-barrel, to place cuttings in suspension and to prevent the cuttings from building up between the core-barrel and sub-surface material. This reduces surface friction at the teeth and along the sides of the core-barrel and thereby reduces the power required for drilling. The pump action is provided by means of a float valve that opens and closes a port in the core-barrel in response to reciprocation of the core-barrel.

This invention relates to a method and apparatus for producing shafts or caissons and in particular relates to a method and apparatus for reducing the frictional drag exerted on a core-barrel While it is being used to cut into bedrock or other sub-surface material. The invention is an improvement in the method described in Patent 3,100,- 381 which issued Aug. 13, 1963 to S. E. Case, et al. for Methods for Producing Caissons, and the cOpending application of Grover C. Gauntt, Jr. et al., Ser. No. 557,806 filed June 15, 1966, for Apparatus and Method of Producing Shaft and Caissons.

In the segment of the construction industry involved in providing load bearing foundations for buildings, bridges, docks, etc., there has been an increased trend toward the requirement for the utilization of larger diameter and progressively deeper shafts to provide reinforced concrete caissons or supporting foundations. As buildings and bridges become taller and heavier and are being built in areas formerly thought unsuitable for supporting such structures, it has become increasingly necessary to develop and innovate techniques for providing deeper shafts in the sub-strata of the earths crust to reach a load-bearing layer, such as bedrock. The depths of these passages or shafts, which must be bored into the earths surface in the production of load-bearing caissons, often reach 100 to 200 feet and, on occasions, may even exceed this.

While a wide variety of equipment has been developed and is in use to initially produce the primary portion of the caisson passage, problems of a substantial nature still exist with respect to the completion of the shaft including the anchoring of the basic structural support of the caisson in the load-bearing or bedrock layer of the earth on which the completed caisson is to rest, and ultimately the structure which it supports. The method and apparatus of the subject invention is addressed to the problem involved in rotating a core-barrel to produce cutting or drilling by the lower serrated or toothed edge of such a core-barrel to thereby drill a socket or anchoring hole into the bedrock. Because of the great weight and size of such core-barrels, even in the absence of friction, a

3,430,448 Patented Mar. 4, 1969 ice considerable amount of power and heavy machinery is required for rotation. However, the rotation of a similar core-barrel in the highly frictional environment of a caisson shaft and in cutting or drilling relationship with the dense supporting earth-layer, requires relatively enormous amounts of power and very heavy machinery to achieve these ends. As the depths of penetration of the core-barrel into bedrock increases and as core-barrel sizes increase, the problem becomes even more acute.

As was set forth at length in the copending application of Grover C. Gauntt, Jr. et al., Ser. No. 557,806, filed June 15, 1966 for Apparatus and Method of Producing Shafts and C-aissons, techniques have been developed to reduce the effective loads developed by large core-barrels. The subject invention is designed primarily to reduce friction and drag factors attendant in the cutting or drilling produced by the lower extremity of the core-barrel by pumping water past the cutting teeth on the core-barrel.

Various other objects and advantages of the invention will hereinafter become more fully apparent from the following description of the drawings appended hereto illustrating presently preferred embodiments of the invention and wherein:

FIG. 1 is a fragmentary cross-sectional view of a corebarrel and pumping apparatus of the invention disposed in cutting or drilling relationship with a dense bedrock layer of earth sub-strata and showing the closure element of the valve of the invention in the position it assumes as the core-barrel is being raised; and

FIG. 2 is a fragmentary cross-sectional view of the core-barrel illustrated in FIG. 1 with the valve closure illustrated in the pumping position.

Since FIGS. 1 and 2 illustrate the same apparatus, like identification numerals will be used with respect to corresponding structures in each of the figures. As is shown, the core-barrel of the invention, generally designated 4 is disposed in a shaft or passage 8, which has been bored into the relatively less dense earth layers, generally indicated 12, by conventional drilling or boring techniques. Water 16 is shown to fill shaft 8 to level A in FIGS. 1 and 2, as well as filling the core-barrel 4. This water is generally subterranean water and rises ordinarily to a level defined by the particular water table of the area in which the construction is being carried out, in this instance to level A. In areas where the Water table is too low or insuificient or where little subterranean water exists, water may be introduced into the open upper portion 20 of the shaft or excavation until it reaches a suitable level.

Referring particularly to FIG. 1, core-barrel 4 is shown to be comprised of a generally cylindrical body 24 and a lower extremity which is provided with a plurality of serrations or teeth 28, which, as was brought out in the above identified copending application, may be made of a composite consisting of a relatively hard Carborundum steel inner layer and a softer outer metal layer which protects and cushions the inner Carborundum steel layer to increase the effectiveness and life of the drilling or cutting action of the teeth. The lower extremity of the core-barrel 4 and the teeth 28 carried thereby are shown to project into a kerf 32 which has been cut by teeth 28 into the bedrock by rotation of the core-barrel.

The upper portion of core-barrel 4 is provided with a partition member 36 which is connected across the diameter of the core-barrel and separates a lower chamber 40 from an upper core-barrel chamber 44. Depending from the partition member 36 are several retaining members, generally designated 48, which have peripherally spaced vertical legs 49 welded to partition member 36 and projecting downwardly therefrom. Each of the legs 49 is provided with generally horizontally inwardly directed flanges 50.

Disposed 'Within retaining members 48 and above horizontal flanges 50 is a valve closure member or piston 60. In the drawing of FIG. 1, the valve closure member 60 is illustrated in its lowermost position with respect to valve chamber 62, which chamber is defined by partition 36, legs 49 and horizontal flanges 50 of retaining members 48. A port 72 which can be opened and closed by valve closure member 60 is provided in partition 36, and it will be seen that valve closure member 60 is confined in chamber 62 below port 72 in partition 36. Valve closure member or piston 60 is smaller in diameter than the diameter of chamber 62 so that the valve member can move up and down and readily reciprocate in chamber 62 to open and close port 72. Valve member or piston 60 is preferably made of a material of low density so that it will float on water, and for example, it has been found in practice that plywood is a suitable material.

A cylindrical member 76 is secured to and extends above partition 36 and forms a generally annular chamber 80 in combination with the cylindrical walls 24 of the core-barrel.

The top of the core-barrel is provided with a cover 84 which is secured to the core-barrel cylinder 24. This cover 84 is, in turn, suitably connected to the lower extremity of the conventional drilling Kelly or rotating shaft 88 so that the entire core-barrel may be rotated by a motive source (not shown) to drill or cut into the bedrock to a predetermined depth. The cover 84 is provided with openings which are located in general alignment with the annular chamber 80 provided by the combination of the cylindrical walls 24 of the core-barrel and cylindrical member 76 connected to partition 36.

FIG. 2 illustrates the core-barrel 4 of the invention with the valve member 60 disposed in its uppermost position in chamber 62 and in abutting relationship with the lower surface of partition 36 thereby closing port 72.

In carrying out the method of the invention following the completion of the basic caisson shaft 8, the corebarrel is lowered into the preformed shaft 8 with the teeth 28 at the lower extremity of the core-barrel in contact with dense or bedrock layer 90 of the earths substrata. The entire core-barrel 4 is rotated through Kelly 88, and the weight of the barrel upon the bedrock layer in combination with its rotation produces the cutting action of the teeth 28 on the rock. As the core-barrel is rotated, kerf 32 is produced by the dislodgement of the components of the bedrock by the teeth 28 of the core-barrel. However, under ordinary circumstances, as the core-barrel cuts a kerf into the bedrock, the bedrock material dislodged by the action of the teeth remains in the kerf and results in the production of very substantial frictional forces which tend to develop a substantial resistance to the rotary motion of the core-barrel.

With the apparatus and method of the present invention, the loose dislodged bedrock material is either placed in suspension in water so that the effects of its frictional resistance is removed as the material is carried from the kerf 32 upwardly along the external periphery of the cylinder 24 and between shaft or passage 8 and the corebarrel 4. This substantially reduces the friction involved in cutting a kerf of suitable depth with the core-barrel and reduces the power required, as well as the strain which'would otherwise be exerted upon the equipment used. Therefore, substantial increases in production have been found to result from the utilization of the method and apparatus of this invention.

In order to produce a pumping action on the water, the entire core-barrel is vertically reciprocated through Kelly 88 by a motive source (not shown) to cause valve member or piston 60 to be cyclicly raised and lowered within the chamber 62 to alternately open and close port 72. Since the core-barrel itself is filled with water through communication by the barrel beneath the water level with: the openings in the barrel cover, 84 the passage lhfollgh cylindrical member 76, port 72, chamber 62, the

spaces between retaining members 48, and the open bottom of the core-barrel. The reciprocation of the core barrel produces a pulsating or pumping force on the water contained in the core-barrel and shaft. After the corebarrel is raised and because valve member 60 is buoyant, it will be normally forced by buoyant forces up against the underside of partition 36 and seating thereagainst closing port 72 (FIG. 2). With the valve member in this position and the core-barrel raised, when the core-barrel is thrust downwardly, the water below partition 36 in chamber 40, in the lower end of the core-barrel, will be forced out of the openings provided in the spaced teeth 28 and upwardly therefrom between the wall defining the primary shaft 8 and the external periphery 24 of the cylindrical core-barrel. The path of the water is shown by arrows 92 in FIG. 2. This water flow from the inside of the core-barrel out therefrom and up along the exterior of the core-barrel carries with it and places in suspension loose and dislodged particles from the kerf being cut by the rotating core-barrel.

When the core-barrel is again raised in shaft 8, the water and any remaining suspended residue between the core-barrel and the shaft wall above the kerf will not be drawn by suction back up into the lower portion of the core-barrel since valve member or piston 60 is held away from port 72 by the pressure of water above it to allow water to freely pass from upper core-barrel chamber 44 and through port 72 into lower chamber 40. In FIG. 1, the flow of water from chamber 44 through port 72 is shown by arrows 94. When the core-barrel reaches the apex of its upward pumping stroke, the buoyant forces on valve member 60 will permit it to float into the position shown in FIG. 2 to close port 72 so that water will be pumped from the lower end of the core-barrel as the barrel is forced downwardly and back into kerf 32.

The continued reciprocation of the core barrel in this manner will effectively serve to purge the kerf of dislodged bedrock material, as well as that between the barrel periphery 24 and the shaft 8, and reduce the frictional resistance exerted upon the barrel during the rotating cutting or drilling process.

As an adjunct to the kerf purging system, the upper portion of the core-barrel is provided with the annular chamber 80, which is defined by the inner peripheral surface of the barrel wall 24, the upper surface of partition member 36 and the outermost surface of cylindrical member 76. As the dislodgement material is carried from between the barrel and the shaft in which it is disposed, the material will pass through the open cover 84 at the top of the core-barrel into the chamber provided within the core-barrel. The dislodged material will settle by gravity into chamber '80 and this chamber thereby serves as a depository for dislodged bedrock material which has been removed from the kerf and prevents it from working its way back down between the barrel and the shaft.

Completion of the caisson can then be carried out in accordance with the method described in the aforesaid copending application or in more conventional methods.

Various modes of carrying out the invention are contemplated as being within the scope of the following claims, particularly pointing out and distinctly claiming the subject matter which is regarded as the invention.

We claim:

1. An apparatus for forming shafts comprising an elongated core-barrel having a chamber, the core-barrel being insertable into a shaft, the chamber opening at opposite ends of the core-barrel, cutting means provided on one of the ends of the core-barrel, connecting means disposed adjacent another end of the core-barrel for connecting the core-barrel to a motive source for rotation, a pump means interposed in the core-barrel between the cutting means and the connecting means, the pump means extending across the chamber of the core-barrel and separating the ends thereof, the pump means including a piston disposed within the chamber of the core-barrel,

and means within the chamber for containing the piston, the piston being reciprocable in the piston containing means for pumping a liquid from one of the open ends of the chamber.

2. An apparatus according to claim 1, wherein the pump means includes a partition member extending across the chamber of the core-barrel to provide first and second chamber portions, the partition member being provided with an opening, the piston containing means defining a web having a plurality of spaced openings forming a piston chamber providing a third chamber portion connected adjacent the partition member and in communication with the opening thereof, the piston is disposed in the third chamber for axial reciprocation therein, and means for producing the generally axial reciprocation of the piston for pumping fluid through the core-barrel and for removing cuttings from adjacent the teeth and external periphery thereof during shaft formation.

3. An apparatus according to claim 2, wherein the third chamber is disposed in the chamber of the corebarrel portion carrying the teeth thereof and the piston is actuated by the relative reciprocation of the third chamber with respect to the piston.

4. An apparatus according to claim 1, wherein a settling means is disposed in the core-barrel on the side of the pump means opposite the cutting means of the corebarrel for deposit and collection of cuttings pumped from adjacent the cutting means and the external periphery of the core-barrel to reduce friction and thereby power requirements in forming shafts.

5. An apparatus according to claim 1, wherein the pump means includes a partition member extending across the chamber of the core-barrel to divide the chamber of the core-barrel into first and second chamber portions, the partition member being provided with an opening establishing communication between the first and second chamber portions, the piston containing means includes a plurality of retaining members connected to the partition member and extending therefrom into one of the chamber portions and in communication with the opening of the partition member to establish communication between the first and second chamber portions, the piston is disposed for generally axial reciprocation between the retaining members, the piston being actuable by the relative generally axial reciprocation of the piston with respect to the retaining members, and stop means at opposite ends of the retaining members for controlling the extent of piston reciprocation.

6. An apparatus according to claim 5, wherein the piston is actuable by the generally axially directed reciprocation of the core-barrel.

7. An apparatus according to claim 5, wherein a settling means formed by the partition member and an upstanding member provided thereon bordering the opening provided therein is disposed in the core barrel on the side of the partition of the pump means opposite the cutting means of the core-barrel for deposit and collection of cuttings carried from the core-barrel.

8. A method of producing a bore comprising the steps of positioning a hollow generally cylindrical cutting member in contact with the surface of a material to be bored within a hollow shaft formed in a sub-strata, the surface of the material being bored having a liquid disposed adjacent thereto, the cutting member is provided with cutting teeth and the cutting member is rotated to impart a cutting motion to the cutting member to dislodge material in the area being bored to produce a kerf of predetermined depth and width in the sub-strata, introducing a portion of the liquid into the hollow cutting member, pumping the liquid through the hollow cutting member and out an end thereof in cutting engagement with the sub-strata, the liquid pumping is produced by a piston positioned within the hollow cylindrical cutting member, the piston being generally axially reciprocated in the cylindrical cutting member by the generally axial reciprocation of the piston with respect to a piston re taining means and the hollow cutting member to produce a liquid flow through the cutting member and out between the teeth thereof to carry dislodged particles from the cutting area and adjacent the outer periphery of the cutting member to reduce the friction and thereby the power requirements of the cutting operation.

9. A method according to claim 8, wherein the cutting member is a core-barrel and upon completion of the cutting operation the core-barrel is permanently anchored in the bed-rock of the hollow shaft.

10. A method according to claim 8, wherein the cutting members is a core-barrel which is rotated to cut a kerf of predetermined depth in the sub-strata of the hollow shaft, the piston of the pump is a floating disc actuated by the reciprocation of the core-barrel to carry dislodged material from the kerf thereof, and a portion of the dislodged material is deposited in the core-barrel above the pump thereof.

References Cited UNITED STATES PATENTS 3,185,226 5/1965 Robbins 61-40 X 3,310,124 3/ 19'67 Farmer 6140 X FOREIGN PATENTS 1,095,408 12/ 1954 France.

15,601 7/ 1903 Great Britain.

JACOB SHAPIRO, Primary Examiner.

US. Cl. X.R. 

